[填空题]
The Moon orbits the Earth such that the same ww 4-jbro1 9kvside aojl gh9lv,-898llp nhw*gg1u lways faces the Earth. Determine the ratio of the Moon’s spin angular momentum (about its own axis) to its orbital angular momentum. (In the latter case, treat the Moon as a particle orbit9*n 8oh uglljl h,w-9gp8l 1gving the Earth.) $\times10^{ -6}$